For many of us, what happened is deeply personal. I called Orlando home during my college years, making lifelong friends in the city that was host to an attack on Sunday. Others have pointed to the ways gay clubs like Pulse serve as a refuge for them in inhospitable communities. Some have described a shared experience with gun violence and their struggle with its aftermath.

But you don't have to have a personal link to the tragedy to feel upset. In fact, your emotions are fundamentally human: Pain as a result of a tragedy, even if you're not involved, is an uncontrollable psychological response.

"At the heart of this is vicarious trauma"

It's difficult to make sense of something so senseless. When you can't, your psyche tries to do it for you. This comes through reading information on the event and then expressing sadness in any way that feels cathartic.

"At the heart of this is a process called vicarious trauma, which is what happens when you watch someone go through an experience like this on the news," David Kaplan, chief professional officer at the American Counseling Association, told The Huffington Post. "It's distressing to watch this kind of suffering because you have no control over it."

Human connection also plays a role, Kaplan says. Not only do people have a biological, inherent understanding of suffering, but that connection runs deeper the more they see parts of themselves in the victims. For example, the shooting is likely to particularly resonate with someone who identifies with the LGBTQ community.

"If you relate to the person who was attacked in any way, you're going to grieve because it's also part of you," Kaplan explained. "And that's perfectly normal and perfectly understandable."

“Even if you’re far removed or living somewhere else, you can still feel traumatized.”

Additionally, Kaplan says you don't need to live close to Orlando to feel close to what happened. The effects are still the same even if you're 1,000 miles away.

"Research shows that it's stressful to watch people go through something like this," Kaplan said. "Even if you're far removed or living somewhere else, you can still feel traumatized."

If you're feeling particularly upset over Sunday's tragedy, experts recommend reaching out to friends and family, exercising self-care and talking to a mental health professional if you need it. But ultimately, the pain you may be experiencing is real -- but so will be the resilience that follows it.

"People are amazingly tough and resilient," Kaplan said. "Human beings can and will recover from trauma eventually."